The use of a non-biological, bridging, antiprotrusio cage in complex revision hip arthroplasty and periacetabular reconstructive oncologic surgery. Is still today a valid option?: A mid/long-term survival and complications' analysis

Introduction Burch-Schneider-like antiprotrusio cages (B-SlAC) still remain helpful implants to bridge severe periacetabular bone losses. The purpose of this study was to evaluate outcomes and estimate both cages' failures and complication risks in a series of B-SlAC implanted in revision of failed total hip arthroplasties (THA) or after resection of periacetabular primary or secondary bone malignancies. Risk factors enhancing the chance of dislocations and infections were checked. Materials and methods We evaluated 73 patients who received a B-SlAC from January 2008 to January 2018. Group A, 40 oncological cases (22 primary tumors; 18 metastases); Group B, 33 failed THAs. We compared both Kaplan-Meier estimates of risk of failure and complication with the cumulative incidence function, taking account the competing risk of death. Cox proportional hazards model was utilized to identify possible predictors of instability and infection. Harris hip score HHS was used to record clinical outcomes. Results Medium follow-up was 80 months (24-137). Average final HHS was 61 (28-92), with no differences within the two groups (p > 0.05). The probabilities of failure and complications were 57% and 26%, respectively, lower in the oncologic group than in the rTHA group (p =0 .176; risk 0.43) (p = 0.52; risk 0.74). Extended ileo-femoral approach and proximal femur replacement (p =0.02, risk ratio = 3.2; p = 0.04, rr = 2.1) were two significant independent predictors for dislocations, while belonging to group B (p = 0.04, rr = 2.6) was predictable for infections. Conclusion Burch-Schneider-like antiprotrusio cages are a classical non-biological acetabular reconstruction method that surgeons should bear in mind when facing gross periacetabular bone losses, independently of their cause. However, dislocation and infection rates are high. Whenever possible, we suggest preserving the proximal femur in revision THA, and to use a less-invasive postero-lateral approach to reduce dislocation rates in non-oncologic cases.

Automated summary

Burch-Schneider-like antiprotrusio cages remain helpful in addressing severe periacetabular bone losses, with higher failure and complication rates in revision THA patients compared to oncologic cases. Significant independent predictors for dislocations were the extended ileo-femoral approach and proximal femur replacement, while THA failures were predicted for infections. Surgeons should consider using less-invasive approaches to reduce dislocation rates in non-oncologic cases.